The instant invention relates to a pressure control system for a convergent-divergent exhaust nozzle of a gas turbine engine, and more particularly to a jet aircraft turbofan engine having either an axi-symetrical (i.e., round) or a 2D (i.e., rectangular) exhaust nozzle.
It is well known that in some applications a jet aircraft turbofan engine having a 2D exhaust nozzle is better suited than one having an axi-symetrical one. One of the advantages of 2D nozzles over axi-symetrical ones is that 2D nozzles can be "vectored" more easily. That is, the trailing edges of the 2D nozzle can be moved either up or down. This deflection of thrust can be used to reduce take-off and landing distances, and increase maneuverability of the aircraft.
It is equally well known that a current significant problem with 2D nozzles is the extremely high air loads which the nozzle flaps actuation system must overcome to properly position the nozzle flaps.